package com.paytong.platform.member.commons.utils;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;

	/** *//** 
	 * <p> 
	 * BASE64编码解码工具包 
	 * </p> 
	 * <p> 
	 * 依赖javabase64-1.3.1.jar 
	 * </p> 
	 *  
	 * @author IceWee 
	 * @date 2012-5-19 
	 * @version 1.0 
	 */  
	public class Base64Utils {  
	  
	    /** *//** 
	     * 文件读取缓冲区大小 
	     */  
	    private static final int CACHE_SIZE = 1024;  
	      
	    /** *//** 
	     * <p> 
	     * BASE64字符串解码为二进制数据 
	     * </p> 
	     *  
	     * @param base64 
	     * @return 
	     * @throws Exception 
	     */  
	    public static byte[] decode(String base64) throws Exception {  
	        return org.springframework.util.Base64Utils.decode(base64.getBytes());  
	    }  
	      
	    /** *//** 
	     * <p> 
	     * 二进制数据编码为BASE64字符串 
	     * </p> 
	     *  
	     * @param bytes 
	     * @return 
	     * @throws Exception 
	     */  
	    public static String encode(byte[] bytes) throws Exception {  
	        return new String(org.springframework.util.Base64Utils.encode(bytes));  
	    }  
	      
	    /** *//** 
	     * <p> 
	     * 将文件编码为BASE64字符串 
	     * </p> 
	     * <p> 
	     * 大文件慎用，可能会导致内存溢出 
	     * </p> 
	     *  
	     * @param filePath 文件绝对路径 
	     * @return 
	     * @throws Exception 
	     */  
	    public static String encodeFile(String filePath) throws Exception {  
	        byte[] bytes = fileToByte(filePath);  
	        return encode(bytes);  
	    }  
	      
	    /** *//** 
	     * <p> 
	     * BASE64字符串转回文件 
	     * </p> 
	     *  
	     * @param filePath 文件绝对路径 
	     * @param base64 编码字符串 
	     * @throws Exception 
	     */  
	    public static void decodeToFile(String filePath, String base64) throws Exception {  
	        byte[] bytes = decode(base64);  
	        byteArrayToFile(bytes, filePath);  
	    }  
	      
	    /** *//** 
	     * <p> 
	     * 文件转换为二进制数组 
	     * </p> 
	     *  
	     * @param filePath 文件路径 
	     * @return 
	     * @throws Exception 
	     */  
	    public static byte[] fileToByte(String filePath) throws Exception {  
	        byte[] data = new byte[0];  
	        File file = new File(filePath);  
	        if (file.exists()) {  
	            FileInputStream in = new FileInputStream(file);  
	            ByteArrayOutputStream out = new ByteArrayOutputStream(2048);  
	            byte[] cache = new byte[CACHE_SIZE];  
	            int nRead = 0;  
	            while ((nRead = in.read(cache)) != -1) {  
	                out.write(cache, 0, nRead);  
	                out.flush();  
	            }  
	            out.close();  
	            in.close();  
	            data = out.toByteArray();  
	         }  
	        return data;  
	    }  
	      
	    /** *//** 
	     * <p> 
	     * 二进制数据写文件 
	     * </p> 
	     *  
	     * @param bytes 二进制数据 
	     * @param filePath 文件生成目录 
	     */  
	    public static void byteArrayToFile(byte[] bytes, String filePath) throws Exception {  
	        InputStream in = new ByteArrayInputStream(bytes);     
	        File destFile = new File(filePath);  
	        if (!destFile.getParentFile().exists()) {  
	            destFile.getParentFile().mkdirs();  
	        }  
	        destFile.createNewFile();  
	        OutputStream out = new FileOutputStream(destFile);  
	        byte[] cache = new byte[CACHE_SIZE];  
	        int nRead = 0;  
	        while ((nRead = in.read(cache)) != -1) {     
	            out.write(cache, 0, nRead);  
	            out.flush();  
	        }  
	        out.close();  
	        in.close();  
	    }  
}
